U.S. patent application number 12/423289 was filed with the patent office on 2009-10-15 for manipulator and method of controlling manipulator.
This patent application is currently assigned to OLYMPUS MEDICAL SYSTEMS CORP.. Invention is credited to Kazuhiko TAKAHASHI, Yoshitaka UMEMOTO.
Application Number | 20090259340 12/423289 |
Document ID | / |
Family ID | 40957840 |
Filed Date | 2009-10-15 |
United States Patent
Application |
20090259340 |
Kind Code |
A1 |
UMEMOTO; Yoshitaka ; et
al. |
October 15, 2009 |
MANIPULATOR AND METHOD OF CONTROLLING MANIPULATOR
Abstract
A manipulator includes: a drive section which electrically
drives a joint; an instruction input section which executes
instruction input; a control section which generates a driving
signal in response to the instruction input; a sensor which detects
an operation status of the joint or the drive section in time
series; a setting section which sets an allowable operation range
of the drive section; a determination section which determines
whether an operation status signal including a detection signal is
within the allowable operation range; and a replacement section
which, in a case when the operation status signal is determined as
deviating from the allowable operation range, replaces the
detection signal with a previous detection signal acquired just
before the determination of deviance in order to generate a driving
signal.
Inventors: |
UMEMOTO; Yoshitaka; (Tokyo,
JP) ; TAKAHASHI; Kazuhiko; (Tokyo, JP) |
Correspondence
Address: |
SCULLY SCOTT MURPHY & PRESSER, PC
400 GARDEN CITY PLAZA, SUITE 300
GARDEN CITY
NY
11530
US
|
Assignee: |
OLYMPUS MEDICAL SYSTEMS
CORP.
Tokyo
JP
|
Family ID: |
40957840 |
Appl. No.: |
12/423289 |
Filed: |
April 14, 2009 |
Current U.S.
Class: |
700/275 ;
901/9 |
Current CPC
Class: |
G05B 2219/37175
20130101; A61B 1/0051 20130101; G05B 2219/45118 20130101; G05B
19/4062 20130101; G05B 2219/42306 20130101; G05B 2219/42329
20130101; B25J 9/1674 20130101; G05B 2219/37522 20130101; A61B
5/065 20130101; G05B 2219/37514 20130101; G05B 2219/42291
20130101 |
Class at
Publication: |
700/275 ;
901/9 |
International
Class: |
B25J 9/04 20060101
B25J009/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 2008 |
JP |
2008-105975 |
Claims
1 A manipulator comprising: a drive section which electrically
drives a turnable joint; an instruction input section which
executes instruction input for rotating the joint; a driving signal
generation section which generates a driving signal for driving the
drive section in response to the instruction input; a sensor which
detects an operation status of the joint or the drive section in
time series; a setting section which sets an allowable operation
range within which the drive section is operable in a case when the
drive section is driven with the driving signal; a determination
section which determines whether an operation status signal
corresponding to the operation status is within the allowable
operation range, the operation status signal at least including a
detection signal detected by the sensor; a control section which,
in a case when the operation status signal is determined as being
within the allowable operation range, generates a driving signal
for a time after the determination using the detection signal; and
a replacement section which, in a case when the operation status
signal is determined as deviating from the allowable operation
range, replaces the detection signal with a previous detection
signal having been determined as being within the allowable
operation range just before a time the operation status signal has
been determined as deviating from the allowable operation range,
and generates a driving signal for a time after the determination
of deviance.
2. The manipulator according to claim 1, further comprising a
memory section which stores the detection signal detected by the
sensor in time series.
3. The manipulator according to claim 1, further comprising a
decision section which decides to execute or stop a determination
operation by the determination section according to a used or
unused status of an energy output device that outputs electric
energy, the energy output device being arranged outside the
manipulator.
4. The manipulator according to claim 1, wherein the sensor
includes an encoder which, when a rotary drive section configuring
the drive section is rotated, detects an angle of the rotation, the
manipulator further comprising a calculation section which
calculates an angular velocity value based on an angle value taken
as the detection signal acquired by the encoder, the angular
velocity value included in the operation status signal.
5. The manipulator according to claim 2, wherein the sensor
includes an encoder which, when a rotary drive section configuring
the drive section is rotated, detects an angle of the rotation, the
manipulator further comprising a calculation section which
calculates an angular velocity value based on an angle value taken
as the detection signal acquired by the encoder, the angular
velocity value included in the operation status signal.
6. The manipulator according to claim 4, wherein the calculation
section also calculates an angular acceleration value which is
included in the operation status signal.
7. The manipulator according to claim 5, wherein the calculation
section also calculates an angular acceleration value which is
included in the operation status signal.
8. The manipulator according to claim 4, wherein the determination
section determines whether the angle value and the angular velocity
value which are included in the operation status signal are within
the allowable operation ranges having been set in terms of angle
and angular velocity, respectively, and the replacement section
replaces the detection signal with the previous detection signal in
a case when at least one of the angle value and the angular
velocity value is found to be deviating from the allowable
operation range.
9. The manipulator according to claim 6, wherein the determination
section determines whether all of the angle value, the angular
velocity value and the angular acceleration value which are
included in the operation status signal are within the allowable
operation ranges having been set in terms of angle, angular
velocity and angular acceleration, respectively, and the
replacement section replaces the detection signal with the previous
detection signal in a case when at least one of the angle value,
the angular velocity value and the angular acceleration value is
found to be deviating from the allowable operation range.
10. The manipulator according to claim 1, wherein the sensor
includes an encoder which, when a rotary drive section configuring
the drive section is rotated, detects an angle of the rotation, and
the determination section determines whether the operation status
signal is within the allowable operation range based on a
determination whether a pulse signal, which is to be outputted
according to an angle of rotation of the rotary drive section as
acquired by the encoder, is within a predetermined frequency
band.
11. The manipulator according to claim 1, wherein the control
section, in a case when the operation status signal including the
detection signal is determined as being within the allowable
operation range, generates a driving signal for the time after the
determination through the use of a difference value derived by
subtracting the detection signal from an instruction input signal
corresponding to the instruction input as a new instruction input
signal, and the replacement section, in a case when the operation
status signal including the detection signal is determined as
deviating from the allowable operation range, generates a driving
signal for the time after the determination of deviance through the
use of a difference value derived by subtracting a previous
detection signal, having been determined as being within the
allowable operation range just before the time when deviance has
been determined, from the instruction input signal as a new
instruction input signal.
12. The manipulator according to claim 2, wherein the control
section, in a case when the operation status signal including the
detection signal is determined as being within the allowable
operation range, generates a driving signal for the time after the
determination through the use of a difference value derived by
subtracting the detection signal from an instruction input signal
corresponding to the instruction input as a new instruction input
signal, and the replacement section, in a case when the operation
status signal including the detection signal is determined as
deviating from the allowable operation range, reads out from the
memory section a previous detection signal, having been determined
as being within the allowable operation range just before the time
when deviance has been determined, and generates a driving signal
for the time after the determination of deviance through the use of
a difference value derived by subtracting the previous detection
signal from the instruction input signal as a new instruction input
signal.
13. The manipulator according to claim 4, wherein the determination
section determines whether the angle value and the angular velocity
value which are included in the operation status signal are within
the allowable operation ranges having been set in terms of angle
and angular velocity, respectively, the control section, in a case
when a determination result indicates that the angle value and the
angular velocity value are within the allowable operation ranges,
generates a driving signal for the time after the determination
through the use of a difference value derived by subtracting the
angle value from an instruction input signal corresponding to the
instruction input as a new instruction input signal, and the
replacement section, in a case when the determination result
indicates that the angle value and the angular velocity value are
deviating from the allowable operation ranges, generates a driving
signal for the time after the determination of deviance through the
use of a difference value derived by subtracting a previous angle
value, having been determined as being within the allowable
operation range just before the time when deviance has been
determined, from the instruction input signal as a new instruction
input signal.
14. The manipulator according to claim 6, wherein the determination
section determines whether all of the angle value, the angular
velocity value and the angular acceleration value which are
included in the operation status signal are within the allowable
operation ranges having been set in terms of angle, angular
velocity and angular acceleration, respectively, and the
replacement section, in a case when at least one of the angle
value, the angular velocity value and the angular acceleration
value is determined as deviating from the allowable operation
range, generates a driving signal for the time after the
determination of deviance through the use of a difference value
derived by subtracting a previous angle value, having been
determined as being within the allowable operation range just
before the time when deviance has been determined, from an
instruction input signal corresponding to the instruction input as
a new instruction input signal.
15. The manipulator according to claim 1, further comprising a
correction section which corrects a shift amount between the
detection signal in a case where the operation status signal
including the detection signal is determined as deviating from the
allowable operation range and the previous detection signal for
replacement, in order to generate a driving signal for the time
after the determination.
16. The manipulator according to claim 1, wherein the replacement
section, in a case when the operation status signal is determined
as deviating from the allowable operation range, replaces the
detection signal with the previous detection signal, while the
replacement section also adds an amount of change, which can be
estimated from a change in the previous detection signal from a
time when the previous detection signal was detected to a time of
the determination, to the previous detection signal, in order to
generate a driving signal for the time after the determination of
deviance.
17. The manipulator according to claim 2, wherein the replacement
section, in a case when the operation status signal is determined
as deviating from the allowable operation range, reads out the
detection signal from the memory section to replace the detection
signal with the previous detection signal, while the replacement
section also uses a replacement signal in which an amount of
change, which can be estimated from a change in the previous
detection signal from a time when the previous detection signal was
detected to a time of the determination, is added to the previous
detection signal, to generate a driving signal for the time after
the determination of deviance.
18. The manipulator according to claim 16, further comprising a
correction section which corrects a shift amount between the
detection signal in a case where the operation status signal
including the detection signal is determined as deviating from the
allowable operation range and the replacement signal, in order to
generate a driving signal for the time after the determination.
19. The manipulator according to claim 1, further comprising a
bendable bending section having a plurality of the joints being
connected thereto.
20. The manipulator according to claim 19, wherein the bending
section is arranged at an elongated flexible insertion section
which is to be inserted into a body.
21. The manipulator according to claim 20, wherein the insertion
section is an insertion section of an endoscope where an objective
optical system is arranged at a distal end portion of the insertion
section, or an insertion section of a treatment instrument where a
treatment section is arranged at the distal end portion of the
insertion section.
22. A method of controlling a manipulator comprising: an
instruction input step for executing instruction input for rotating
a turnable joint to a target angle; a first driving step for
driving the joint via a drive section with a driving signal based
on an instruction input signal from the instruction input step; a
setting step for setting an allowable operation range allowed in a
case of driving the joint; an acquiring step for acquiring, while
the joint is rotating according to a driving signal, an angle of
rotation of the joint as a sensor value in time series; a
determining step for determining whether the sensor value acquired
in the acquiring step is within the allowable operation range; and
a second driving step in which, in a case when the sensor value is
determined as being within the allowable operation range, a driving
signal for a time after the determination is generated using the
sensor value, and in a case when the sensor value is determined as
deviating from the allowable operation range, a driving signal for
a time after the determination is generated by replacing the sensor
value with a previous sensor value having been determined as being
within the allowable operation range just before the time when
deviance is determined.
23. The method of controlling a manipulator according to claim 22,
wherein in the second driving step, in a case when the sensor value
is determined as being within the allowable operation range, a
difference value derived by subtracting the sensor value from the
instruction input signal is used as a new instruction input signal
to generate a driving signal for the time after the determination,
and in a case when the sensor value is determined as deviating from
the allowable operation range, a difference value derived by
subtracting the previous sensor value, having been determined as
being within the allowable operation range just before the time
when deviance is determined, from the instruction input signal is
used as a new instruction input signal to generate a driving signal
for the time after the determination.
24. The method of controlling a manipulator according to claim 22,
further comprising a calculating step for calculating an angular
velocity value and an angular acceleration value based on the
sensor value acquired in the acquiring step, wherein in the
determining step, it is determined whether the angular velocity
value and the angular acceleration value as calculated in the
calculating step are within allowable operation ranges having been
set in terms of angular velocity and angular acceleration,
respectively, and in the second driving step, in a case when at
least one of the acquired sensor value on the angle, the angular
velocity value and the angular acceleration value is determined as
deviating from the allowable operation range, the sensor value is
replaced with the previous sensor value.
Description
[0001] This application claims benefit of Japanese Application No.
2008-105975 filed in Japan on Apr. 15, 2008, the contents of which
are incorporated by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a manipulator for driving a
turnable joint.
[0004] 2. Description of the Related Art
[0005] An endoscope which is capable of monitoring inside a body
and performing appropriate treatments using treatment instruments
where necessary has been used widely in the medical field. The
endoscope usually has a bending section, configured as having a
plurality of joints being connected in a turnable manner, at a
distal end side of its insertion section in order to be able to be
easily inserted into a flexural body.
[0006] One type of an endoscope would be a hand-operated type in
which the bending section is bend-driven through manual operation
(where operating force is required). An electromotive bending type
endoscope has also been put to practical use. In the electromotive
bending type endoscope, that is, a type that has a manipulator,
electrical driving means such as a motor is used in bend-driving
the bending section for the purpose of further enhancing
operability.
[0007] With respect to a treatment instrument as well, some
instruments have achieved further enhanced operability by adopting
a manipulator which is configured to drive the bending section
having a plurality of joints by driving means such as a motor
through an instructing operation on a proximal side.
[0008] As one example in the prior art, for instance, Japanese
Patent Application Laid-Open Publication No. 10-315173 discloses a
device having a secondary filter as being a modeled position
control section as well as a position control model section where
positional instruction is received; and malfunction detecting means
configured as including the secondary filter, a comparator, an
absolute value transforming section, and a subtractor, the
malfunction detecting means functioning to compare an output signal
from the position control model section with a position signal
indicating an actual position of an electrical motor that drives a
robot, and thus detect malfunction in the robot when a difference
between the compared two signals becomes equal to or greater than a
predetermined value.
[0009] With this device, when a difference between a signal from an
input system and an output signal at a time when the electrical
motor is driven in response to the input signal from the input
system is equal to or greater than a predetermined value, it is
determined that there is malfunction in the robot, whereby possible
malfunction can be found in an early stage where further runaway of
the robot can be stopped.
SUMMARY OF THE INVENTION
[0010] According to an aspect of the present invention, a
manipulator includes: a drive section which electrically drives a
turnable joint; an instruction input section which executes
instruction input for rotating the joint; a driving signal
generation section which generates a driving signal for driving the
drive section in response to the instruction input; a sensor which
detects an operation status of the joint or the drive section in
time series; a setting section which sets an allowable operation
range within which the drive section is operable in a case when the
drive section is driven with the driving signal; a determination
section which determines whether an operation status signal
corresponding to the operation status is within the allowable
operation range, the operation status signal at least including a
detection signal detected by the sensor; a control section which,
in a case when the operation status signal is determined as being
within the allowable operation range, generates a driving signal
for a time after the determination using the detection signal; and
a replacement section which, in a case when the operation status
signal is determined as deviating from the allowable operation
range, replaces the detection signal with a previous detection
signal having been determined as being within the allowable
operation range just before a time the operation status signal has
been determined as deviating from the allowable operation range,
and generates a driving signal for a time after the determination
of deviance.
[0011] According to an aspect of the present invention, a method of
controlling a manipulator includes: an instruction input step for
executing instruction input for rotating a turnable joint to a
target angle; a first driving step for driving the joint via a
drive section with a driving signal based on an instruction input
signal from the instruction input step; a setting step for setting
an allowable operation range allowed in a case of driving the
joint; an acquiring step for acquiring, while the joint is rotating
according to a driving signal, an angle of rotation of the joint as
a sensor value in time series; a determining step for determining
whether the sensor value acquired in the acquiring step is within
the allowable operation range; and a second driving step in which,
in a case when the sensor value is determined as being within the
allowable operation range, a driving signal for a time after the
determination is generated using the sensor value, and in a case
when the sensor value is determined as deviating from the allowable
operation range, a driving signal for a time after the
determination is generated by replacing the sensor value with a
previous sensor value having been determined as being within the
allowable operation range just before the time when deviance is
determined.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a block diagram showing an overall configuration
of an endoscope treatment system that includes a first embodiment
of the present invention;
[0013] FIG. 2 is a flow chart showing contents of processes in an
operation of the endoscope treatment system that includes the first
embodiment of the present invention;
[0014] FIG. 3A and FIG. 3B are diagrams showing examples of an
angle of a motor configuring an active mechanism as the motor is
rotated by a constant output, and a sensor value of angle acquired
by a sensor;
[0015] FIG. 4A and FIG. 4B are diagrams showing examples of an
angular velocity of the motor configuring the active mechanism as
the motor is rotated by the constant output, and an angular
velocity calculated based on the sensor value acquired by the
sensor;
[0016] FIG. 5A and FIG. 5B are diagrams showing examples of an
angular acceleration of the motor configuring the active mechanism
as the motor is rotated by the constant output, and an angular
acceleration calculated based the sensor value acquired by the
sensor;
[0017] FIG. 6 is a flow chart showing contents of processes in a
case of error being determined;
[0018] FIG. 7 is an explanatory diagram of an operation, according
to a variant example, in a case of error being determined;
[0019] FIG. 8 is a diagram showing a specific configuration example
of peripheral equipment as well as an endoscope shown in FIG.
1;
[0020] FIG. 9 is a diagram showing specific configuration examples
of a treatment instrument shown in FIG. 1 and a control device of
the treatment instrument;
[0021] FIG. 10 is a block diagram showing an overall configuration
of an endoscope treatment system that includes a second embodiment
of the present invention;
[0022] FIG. 11 is a flow chart showing contents of processes
related to energy output, according to the second embodiment;
and
[0023] FIG. 12 is a configuration diagram of a section that
determines validity of a sensor value based on whether or not an
output of the sensor value is within a predetermined frequency
band.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] In the following, embodiments of the present invention will
be described with reference to the attached drawings.
First Embodiment
[0025] FIG. 1 shows an endoscope treatment system (or an endoscope
system) 1 that includes a manipulator according to a first
embodiment of the present invention.
[0026] This endoscope treatment system 1 includes an active
endoscope (hereinafter to be referred to simply as endoscope) 2; an
active treatment instrument (hereinafter to be referred to simply
as treatment instrument unless the term may sound confusing) 3
which is used along with the endoscope 2 and performs treatments; a
light source device 4 which supplies the endoscope 2 with
illuminating light, a display processor 5 which performs signal
processing with respect to a signal from an image pickup section of
the endoscope 2; and a display device 6 which displays an endoscope
image that corresponds to an image signal from the display
processor 5.
[0027] Moreover, the endoscope treatment system 1 includes a
control device 8 which performs drive control on an endoscope
active mechanism (to be referred to as active mechanism) 7A as
arranged in the endoscope 2 and a treatment instrument active
mechanism (to be referred to as active mechanism) 7B as arranged in
the treatment instrument 3; and an endoscope instruction input
device (to be referred to as instruction input device) 9A and a
treatment instrument instruction input device (to be referred to as
instruction input device) 9B which provides instruction inputs for
driving the respective active mechanisms 7A and 7B. The active
mechanisms 7A and 7B, in specific terms, are configured with motors
as being rotary drive sections (drive sections in the broad sense)
which actively (electrically) rotation-drive a bending section
where joints are arranged.
[0028] The control device 8 includes an endoscope control section
(to be referred to as control section) 10A which drives and
controls the active mechanism 7A based on an instruction input from
the instruction input device 9A and a treatment control section (to
be referred to as control section) 10B which drives and controls
the active mechanism 7B based on an instruction input value from
the instruction input device 9B.
[0029] The active mechanisms 7A and 7B have an endoscope sensor (to
be referred to as sensor unless the term may sound confusing) 11A
and a treatment instrument sensor (to be referred to as sensor
unless the term may sound confusing) 11B, respectively, which are
attached to driving axes or the like, to serve as sensors to detect
(or acquire as measured values) operation statuses (e.g. angles, or
positions in the broad sense, indicating drive amounts) of the
active mechanisms 7A and 7B. These sensors 11A and 11B may be
encoders, for example, and detect rotation angles of the motors
that configure the active mechanisms 7A and 7B.
[0030] The control device 8 (the control section 10I (I indicates A
or B)) generates a driving signal for driving the active mechanism
7I being an instruction target based on an instruction input signal
corresponding to a target driving angle having been inputted as an
instruction input from the instruction input device 9I operated by
an operator, and thus drives the active mechanism 7I.
[0031] Accordingly, the control section 10I functions as a driving
signal generation section for producing (generating) a driving
signal.
[0032] The operation status in terms of a driven angle of the
active mechanism 7I as being driven based on the driving signal is
detected (acquired) by the sensor 11I, and the detected sensor
value is inputted to the control device (control section 10I) as a
detection signal.
[0033] Thus, the active mechanism 7I is driven in time series (in
time course) based on the driving signal that corresponds to the
instruction input signal, while the operation status of the active
mechanism 7I is detected and acquired as a sensor value by the
sensor 11I in time series.
[0034] The control section 10I takes the detected sensor value as a
control signal and subtracts the control signal from the
instruction input signal to calculate a difference value
(difference signal). Then the control section 10I takes the
difference value as a new instruction input signal to generate a
corresponding driving signal (i.e. a driving signal after the
sensor value has been acquired), and thus controls the active
mechanism 7I.
[0035] More specifically, when the active mechanism 7I is driven
such that the angle thereof becomes the target driving angle
indicated by the instruction input signal having been inputted as
an instruction input, a resultant driven angle is detected by the
sensor 11I, and then a difference value between the two signals
(angles) is detected, on the basis of which the driving signal is
feed-back controlled by the sensor value of the sensor 11I such
that the difference value becomes "0".
[0036] By such feed-back control, the active mechanism 7I can be
promptly set to the target driving angle having been inputted by
the instruction input device 9I as the instruction input.
[0037] In this way, by such feed-back control, the active mechanism
7I can be controlled appropriately by a closed-loop. Moreover, in
order to achieve further improved reliability, the control device
8, for example, is provided with a sensor acquisition result
determination section (hereinafter to be referred to simply as
determination section) 12 which acquires a sensor value, as being a
detection signal, detected by the sensor 11I and determines whether
the sensor value corresponds to an operation status signal that is
in a normal state in terms of time.
[0038] Therefore, the determination section 12 takes in sensor
values from both the sensors 11A and 11B through the control
sections 10A and 10B, respectively. Meanwhile, it is also possible
to arrange such that the determination section 12 takes in the
sensor values directly from the sensors 11A and 11B not through the
control sections 10A and 10B.
[0039] Furthermore, the control device 8, for example, is provided
with an active mechanism characteristic storage section 13 where
active mechanism characteristics (specifically, these active
mechanism characteristics are: a rated output of the motor;
operation parameters such as the maximum number of rotations; and
parameters such as inertia moment, output voltage) that determine
the characteristics of both the active mechanisms 7A and 7B are
stored, and an allowable operation range setting section (to be
referred to as setting section) 14 which sets an allowable
operation range, defined as an operation range allowed to the
active mechanism 7I within an operable range within which the
active mechanism 7I is physically operable under a condition that
the active mechanism 7I is driven based on operation parameters
that can be specified by the active mechanism characteristics and
the condition (information) indicated by the instruction input
signal from the instruction input device 9I.
[0040] The determination section 12 allows the sensor values (i.e.
data on angles as being sensor acquisition information) acquired by
each sensor 11I to be stored in a memory section 15 in time series,
and determines validity of an operation status signal, which at
least includes the sensor value (angle in particular), by
determining whether the operation status signal is within the
allowable operation range based on the information about the
allowable operation range having been outputted from the setting
section 14.
[0041] That is, when the operation status signal is found to be
within the allowable operation range, the determination section 12
determines that the operation status signal is normal or valid,
whereas when the operation status signal is found to be deviating
from the allowable operation range, the determination section 12
determines that the operation status signal is not valid due to
problems such as noise, i.e. the determination section 12
determines that the operation status signal is in abnormal or in an
error state. For instance, in a case where the operation status
signal of the sensor value (angle) indicated by is deviating from
the allowable operation range, the operation status signal will be
determined as a sensor value error.
[0042] In the case when the operation status signal is determined
as being valid, the determination section 12 does not cause any
action directed to the control section 10I. In the case when the
operation status signal is determined as being invalid, the
determination section 12 reads out from the memory section 15 the
previous data on the angle having been acquired just before that
determination process and determined as valid. Then the
determination section 12 outputs the read out data as a replacement
signal to the control section 10I, the replacement signal being a
signal for replacing the sensor value (determined as invalid) of
the sensor 11I with the previous sensor value having been
determined as valid. Thus, the determination section 12 has a
replacement section 16 for outputting the replacement signal.
[0043] Meanwhile, in the case when the memory section 15 is to
store the sensor values in time series, it is possible to arrange
such that the memory section 15 also stores the determination
results as obtained by the determination section 12. Moreover, in
storing the sensor value, it can be arranged such that the sensor
value is stored as being associated with the time of storage.
[0044] In this way, according to the present embodiment, in the
case when the operation status signal is determined as deviating
from the allowable operation range and thus as being abnormal or an
error, the previous sensor value having been determined as valid
just before the error is determined, is used as a predetermined
condition considered appropriate, in controlling the active
mechanism 7I so as to continue operating.
[0045] In the case when the operation status signal is determined
as being valid (by the determination section 12), the control
section 10I uses the sensor value from the sensor 11I as a control
signal for controlling the driving signal. On the other hand, in
the case when the operation status signal is determined as being
abnormal, the control section 10I uses the replacement signal
outputted from the determination section 12 as the control signal
(instead of the sensor value of the sensor 11I).
[0046] In FIG. 1, although the setting section 14 and the
determination section 12 are shown in different blocks, it is
possible to configure the determination section 12 as including the
setting section 14.
[0047] The configuration of the manipulator is not limited to the
block configuration as shown in FIG. 1. In the case when the
determination section 12 determines that the operation status
signal is deviating from the allowable operation range and thus is
abnormal or an error, it is possible to arrange such that the
replacement section 16, for example, uses the previous sensor value
having been determined as valid just before the error is
determined, in order to generate a driving signal for a time after
the determination.
[0048] That is, in the case when the operation status signal is
determined as deviating from the allowable operation range, it is
possible to arrange such that the replacement section 16 uses the
previous sensor value in generating a driving signal for a time
after the determination.
[0049] As will be described in terms of an operation example later
on, the determination section 12 not only determines whether the
data on the angle as acquired directly from the sensor 11I is
within the allowable operation range but also determines whether
data on angular velocity, angular acceleration, etc. are within the
allowable operation ranges. In this way, it is arranged such that
the determination section 12 is capable of performing
determinations with higher precision.
[0050] For such purpose, the determination section 12, has a
calculation section 17 which calculates, based on the data on angle
as acquired by the sensor 11I, an angular velocity on the basis of
time dependent change in the angle in a short period of time, and
further calculates, based on the information on the angular
velocity as calculated, an angular acceleration based on time
dependent change in the angular velocity in a short period of time.
Furthermore, the setting section 14 sets the allowable operation
range not only with respect to the angle but also with respect to
the angular velocity and the angular acceleration.
[0051] As will be described in more detail with reference to FIG.
3A, etc., practically, the angle, which is taken as the operation
status signal, at each time point in the passage of time is
monitored and determined whether it is within the allowable
operation range. Therefore, change in the angle in a short period
of time will be determined whether it is within an allowable
operation range, or in other words, within an allowable operation
change range, for that period of time.
[0052] In the endoscope treatment system 1 according to the present
embodiment, a manipulator 20, as shown in FIG. 1, includes the
endoscope 2, the treatment instrument 3, the control device 8, and
the instruction input devices 9A and 9B. In a configuration example
shown in FIG. 8, the display processor 5 and the display device 6
are also included in the manipulator as parts that form a display
mechanism of the manipulator.
[0053] The display processor 5 shown in FIG. 1 controls the amount
of illuminating light from the light source device 4 based on
luminance information indicated by a video signal, for
instance.
[0054] Next, an operation according to the present embodiment will
be described with reference to a flow chart of FIG. 2. FIG. 2 shows
procedures in a method of controlling the manipulator according to
the present embodiment. In the following, an operation in a case
where the active mechanism 7A of the endoscope 2 is actively driven
will be described, for example. As power is supplied to the
endoscope treatment system 1 shown in FIG. 1, the control device 8,
etc. start operating.
[0055] Then at step S1a indicated in FIG. 2, the setting section 14
as arranged inside the control device 8 sets an allowable operation
range as being a predetermined range where the active mechanism 7A
is physically operable, based on operation parameters (of the
active mechanism 7A) that can be specified by the active mechanism
characteristics (being stored in the active mechanism
characteristic storage section 13) and an initial condition (which
is to be ignored when it is undecided, and will be considered in a
next loop) directed by the instruction input device 9A. By this
setting, allowable operation ranges with respect to the angle,
angular velocity and angular acceleration are set for the driving
of the active mechanism 7A.
[0056] Then at step S1b following step S1a, the control section 10A
drives the active mechanism 7A based on the instruction input
signal from the instruction input device 9A. Then at step S2, the
sensor 11A acquires a sensor value with respect to the driven angle
as a measured value.
[0057] At step S3, the determination section 12 calculates the
angular velocity and the angular acceleration based on the sensor
values with respect to the angle as acquired by the sensor 11A.
That is, the angle, the angular velocity and the angular
acceleration, to be regarded as an operation status signal, are
calculated by the determination section 12. With respect to a case
shown in FIG. 3A, which will be described in more detail later on,
angular change in a short period of time as the angle will be
detected.
[0058] Then at a subsequent step S4, the determination section 12
compares the calculated values of the angle, the angular velocity
and the angular acceleration, regarded as the operation status
signal, with the allowable operation ranges with respect to the
angle, the angular velocity and the angular acceleration, which
have been set by the setting section 14, in order to determine
whether each of the values is within the corresponding allowable
operation range.
[0059] Then at step S5, it is determined whether all the values of
the angle, the angular velocity and the angular acceleration are
within the allowable operation ranges. In other words, the validity
of these values is determined. When it is determined that all the
values of the angle, the angular velocity and the angular
acceleration are within the allowable operation ranges, i.e. when
it is determined that the values are valid, the control section
10A, at step S6, generates a driving signal for a next time based
on the value of the angle as acquired by the sensor 11A.
[0060] Then at step S8, the driving signal is supplied to the
active mechanism 7A, whereby the active mechanism 7A is driven.
[0061] Meanwhile, if it is determined at step S5 that at least one
of the values of the angle, the angular velocity and the angular
acceleration is not within the allowable operation range, i.e. when
it is determined that the value is invalid, the process of step S7
is carried out.
[0062] In this case, the determination section 12 reads out from
the memory section 15 the latest previous data on the angle stored
in the memory section 15 (i.e. the previous data on the angle
acquired just before the time where the value is determined
invalid), having been determined as being within the allowable
operation range, and replaces the value of the angle as acquired by
the sensor 11A with the read out data on the angle in order to
generate a driving signal. For a case in that the previous data on
the angle acquired by the sensor 11A has not been stored in the
memory section 15 with respect to the initial processing loop, it
is being set such that an initial value (e.g. 0.degree.) should be
used. Then the operation proceeds to a subsequent step S8.
[0063] After step S8, using information from a new instruction
input signal, the setting section 14 updates the set values of the
allowable operation ranges having been set based on the previous
operation parameters. Then, the operation goes back to step S2. In
this way, when driving conditions of the active mechanism 7A are
changed due to the change in the operation parameters of the active
mechanism 7A, the allowable operation ranges are updated complying
with the change.
[0064] Then, the determination section 12 determines whether the
operation status signal with respect the angle, or the like, as
acquired by the sensor 11A is within the updated allowable
operation range. When the determination result indicates that the
operation status signal is valid, the control section 10A generates
a driving signal based on the value of the angle as acquired by the
sensor 11A. Meanwhile, if the determination result indicates that
the operation status signal is invalid, the control section 10A
generates a driving signal based on the latest previous data on the
angle stored in the memory section 15, having been determined as
valid, the latest previous data on the angle being obtained from
the memory section 15 through the replacement section 16.
[0065] By executing such drive control, if the sensor value
acquired by the sensor 11A or other values of the operation status
signal derived based on that sensor value come to invalid states
while an operator is performing some medical treatment such as an
endoscopic examination or the like using the active mechanism 7A of
the endoscope 2, the drive control on the active mechanism 7A can
be continued. Therefore, the medical treatment will not be forced
to abnormal termination. Next, a specific example of the operation
of the active mechanism 7A in terms of the processes shown in FIG.
2 will be described with reference to FIG. 3A to FIG. 5A.
[0066] FIG. 3A, FIG. 4A and FIG. 5A are graphs showing time
dependent changes in angle .theta., angular velocity V and angular
acceleration A when the active mechanism 7A of the endoscope 2 is
actually driven with a constant rated output. FIG. 3B, FIG. 4B and
FIG. 5B are graphs showing changes in angle .theta., angular
velocity V and angular acceleration A calculated by the calculation
section 17 inside the determination section 12 based on sensor
values (i.e. raw data equivalent to angles) as acquired by the
sensor 11A.
[0067] FIG. 3B shows an example of a case where a sensor value
error or a sensor value acquisition error has occurred. In the
present embodiment, a sensor value error can be defined as a
counter error (counting error) with respect to an output pulse of
an encoder, for example, which could occur due to a waveform of the
encoder being disturbed by noise, etc.
[0068] As shown in FIG. 3A, since the active mechanism 7A is driven
with a constant rated output, the number of rotations with the
motor that configures the active mechanism 7A becomes constant,
except at a starting time, whereby the angle becomes larger by the
same degrees with respect to time. That is, the angular change
.DELTA..theta. per short unit time At becomes constant.
[0069] In a practical sense, there may be a case in which the
number of rotations is rendered unstable due to a load, such as
disturbance, placed on the endoscope 2. However, the case of FIG.
3A is supposed to be an example where influence of such load on the
value of the angular change .DELTA..theta. is small enough.
[0070] As shown in FIG. 4A and FIG. 5A, the angular velocity V and
the angular acceleration A change with time. Specifically, as shown
in FIG. 4A, the angular velocity V becomes a constant angular
velocity V.sub.0 except in a time around the starting time.
[0071] As shown in FIG. 5A, the angular acceleration A changes in a
peaking manner (with a peak value being "A.sub.0") only in a time
around the starting time, and the value thereof becomes 0 from
after that time around the starting time.
[0072] In the case where the active mechanism 7A of the endoscope 2
is driven with the operation parameter as being the constant rated
output condition shown in FIG. 3A, the setting section 14 sets the
allowable operation ranges (usually, such allowable operation range
is a range with a lower limit and a higher limit where values under
normal status are included) with respect to the angle .theta. or
the angular change (angular inclination) .DELTA..theta., the
angular velocity V and the angular acceleration A with which the
motor configuring the active mechanism 7A becomes physically
operable.
[0073] In FIG. 3A, the allowable operation range is shown in terms
of the angular change .DELTA..theta., but when the allowable
operation range is to be shown in terms of the angle .theta., it
will change approximately linearly with the passage of time.
[0074] For example, in terms of the angular change .DELTA..theta.,
the allowable operation range will be
".DELTA..theta.thl<.DELTA..theta.thu", whereas the allowable
operation ranges in terms of the angular velocity V and the angular
acceleration A will be "Vthl<Vthu" and "Athl<Athu",
respectively.
[0075] In a normal (valid) status, the allowable operation ranges
will be ".DELTA..theta.thl<.DELTA..theta.<.DELTA..theta.thu",
"Vthl<V<Vthu" and "Athl<A<Athu", respectively.
[0076] In this example, although the allowable operation ranges in
terms of the angular velocity V and the angular acceleration A are
shown as constant values, there may be cases where it is better
(easy to determine) if the allowable operation ranges are set in
terms of angular velocity change .DELTA.V and angular acceleration
change .DELTA.A, depending on the operation parameters.
[0077] In FIG. 3A to FIG. 5B, the graphs are simplified, and only
the values .DELTA..theta.thu, Vthu, and Athu on the upper limit
sides are shown. Moreover, for the sake of simplicity, the examples
represented by the graphs show the values .DELTA..theta.thu, Vthu,
and Athu on the upper limit sides of the allowable operation ranges
as constant values.
[0078] Meanwhile, the sensor 11A detects the angle of the active
mechanism 7A (motor) every short unit time .DELTA.t. The sensor
value acquired by the sensor 11A is inputted to the determination
section 12, where the calculation section 17 inside the
determination section 12 calculates the angular change
.DELTA..theta. in the unit time .DELTA.t based on the sensor value;
the angular velocity V based on time dependent change in the angle;
and the angular acceleration A based on time dependent change in
the angular velocity.
[0079] Here, since the angular change .DELTA..theta. is calculated
almost uniquely from the sensor value, it is possible to interpret
that the calculation section 17 calculates the angular velocity V
(or the angular velocity change) and the angular acceleration A (or
the angular acceleration change) based on the angle .theta. or the
angular change (the information on the angle .theta. or the angular
change).
[0080] In FIG. 3B, FIG. 4B and FIG. 5B, representative points in
the passage of time t are shown as A', B, C and D. It is assumed
that from point A' around the starting point to point B after the
angular velocity becomes constant (at a value V1), and further up
to point C after that, the sensor value of the sensor 11A is
normal, whereas an error occurs in the sensor value between point C
and point D.
[0081] Points E and F in FIG. 3B are drawn for the purpose of
explaining the processes according to the present embodiment in the
case when the error occurs between points C and D, the processes
supposed to be performed after the error has occurred between
points C and D. As will be described below, in the case when the
error occurs, the active mechanism 7A will be controlled
substantially using sensor values such as those at point D' (i.e. a
sensor value at point C), point E' and point F'.
[0082] In FIG. 3B, the unit time .DELTA.t around point B, for
example, is shown as .DELTA.t1, and a value of change in the angle
detected by the sensor 11A in that case is shown as
.DELTA..theta.1.
[0083] As shown in FIG. 5B, the angular acceleration A takes a
peaking form (with a peak value being "A1") around the starting
point A', and maintained at 0 until just before point C. Then, in
the unit time .DELTA.t (i.e. .DELTA.t2) between point C and point
D, the angular acceleration A greatly changes due to disturbance by
noise, for example.
[0084] In response to such change, the angular velocity V and the
angular acceleration A as calculated from the sensor value of the
sensor 11A change in ways shown in FIG. 4B and FIG. 5B.
[0085] For example, the angular velocity V changes in a form of a
precipitous triangular waveform, where it becomes a peak value V2
at a time just before point D from a value V1 at point C and then
precipitously returns to V1. The angular acceleration A exhibits a
characteristic in that it rises more precipitously up to a peak
value A2, after which it drops precipitously down to a negative
peak value A3 and then precipitously rises again to become 0.
[0086] In FIG. 3B, FIG. 4B and FIG. 5B, the angular change
.DELTA..theta. (i.e. .theta.3-.theta.2), the angular velocity V and
the angular acceleration A, as calculated based on the sensor value
between point C and point D, exceed .DELTA..theta.thu, Vthu and
Athu, which are their allowable operation ranges. Therefore, the
determination section 12 determines that the angular change
.DELTA..theta., the angular velocity V and the angular acceleration
A in this case are deviating from the allowable operation ranges,
and thus are errors.
[0087] In the examples shown by FIG. 3B, FIG. 4B and FIG. 5B, the
angular change .DELTA..theta., the angular velocity V and the
angular acceleration A, as calculated based on the sensor value
between point C and point D, exceed .DELTA..theta.thu, Vthu and
Athu, respectively. However, even with only one of the values being
found deviating from the allowable operation range, an error will
be determined. In such case, the following controlling process will
be carried out.
[0088] The determination section 12 determines that an angle
.theta.3 as being a sensor value at point D is an error. Then, the
determination section 12 does not use that value but takes an angle
.theta.2, as being a sensor value acquired at a time just before
.DELTA.t2 with which an error was not determined, to be a sensor
value of a replacement signal, and transmits that replacement
signal to the control section 10A.
[0089] The control section 10A controls to generate a driving
signal using this replacement signal. Accordingly, as shown in FIG.
3B, in stead of the sensor value at point D, the sensor value at
point C, i.e. a sensor value at point D', is used in controlling
the active mechanism 7A.
[0090] Moreover, the determination section 12 stores information on
the sensor value as being found to be an error in the memory
section 15, for instance. Specifically, the determination section
12 stores a value ".theta.3-.theta.2", for example, as a correction
value W in the memory section 15. Then, the determination section
12 corrects the sensor value (of the sensor 11A) acquired from
after point D with the correction value W. Thus, the determination
section 12 functions as a correction section that corrects a sensor
value in a case when an error occurs. Specifically, a sensor value
acquired at point E after the unit time At from point D will
include the sensor value with which the error has occurred unless
corrected. Therefore, a sensor value at point E' as corrected with
the correction value W is used (in this case, a value derived by
subtracting the correction value W from the sensor value).
Likewise, for point F after point E, a sensor value at point F' as
corrected with the correction value W will be used as a
corresponding sensor value.
[0091] Meanwhile, it is possible to reconfigure the sensor 11A
itself so that the sensor 11A will be able to output a value with a
correct sensor value. In such case, however, the sensor 11A needs
to be reset whereby the operation is required to be stopped (and
restarted) in the middle. To cope with this, by the correction with
the above-mentioned correction value, it is possible to allow the
operation to continue smoothly without having to stop in the
middle.
[0092] FIG. 6 shows processes taken in the above-described case in
which the error occurs, that is, FIG. 6 shows the content of the
process at step S7 in FIG. 2 in more detail.
[0093] In the examples shown by FIG. 3A to FIG. 5B, or in the case
when at least one of the angle indicated by the sensor value or the
angular change .DELTA..theta., the angular velocity V, and the
angular acceleration A is found to be deviating from the allowable
operation range, i.e. in the case when the determination section 12
determines that an error has occurred, at step S5 in FIG. 2, the
determination section 12, at step S11 indicated in FIG. 6, reads
out from the memory section 15 the sensor value (angle .theta.2
shown in FIG. 3B) having been acquired just before the occurrence
of the error.
[0094] Then at step S12, the determination section 12 outputs the
sensor value .theta.2 to the control section 10A as a replacement
signal that replaces the sensor value .theta.3 at the occurrence of
the error.
[0095] Then at step S13, the control section 10A replaces the
sensor value .theta.3 at the occurrence of the error with the
replacement signal and generates a driving signal.
[0096] Meanwhile, at step S14, the determination section 12 takes a
shift amount, for example, between the sensor value .theta.3 at the
occurrence of the error and the sensor value .theta.2 acquired at
the time just before the occurrence of the error to generate a
correction value W.
[0097] Then at step S15, the determination section 12 uses the
correction value W to correct the sensor value acquired after the
sensor value .theta.3 at the occurrence of the error. Moreover, the
determination section 12 transmits the correction value W to the
control section 10A, whereby the control section 10A uses the
correction value W to correct the sensor value acquired after the
sensor value .theta.3 with which the error has occurred, and
generates a driving signal.
[0098] In this case, with a configuration where the sensor value of
the sensor 11A is outputted to the control section 10A through the
determination section 12, the correction process using the
correction value W at the side of the control section 10A is not
necessary.
[0099] By such drive control, as shown in FIG. 3B for instance,
even when an error occurs in the sensor value during the operation
of the active mechanism 7A, the active mechanism 7A can be
controlled continuously with a response delay corresponding to a
period of time .DELTA.t2 in which the error occurred. Therefore,
the operation of the active mechanism 7A does not need to be
stopped and terminated (i.e. forced to abnormal termination) due to
the occurrence of the error.
[0100] Accordingly, even when an error occurs, a user, such as an
operator, will be able to continue the operation by the active
mechanism 7A of the endoscope 2 without having the operation forced
to abnormal termination due to the occurrence of the error. Thus,
operability can be improved to a considerable extent.
[0101] Although the description of the operation which has been
given referring to FIG. 3A to FIG. 6 is about the case of the
endoscope 2, it can also be applied to a case of the active
mechanism 7B of the treatment instrument 3.
[0102] FIG. 7 shows a content of a process (error process) at an
occurrence of an error according to a variant example. The
above-described error process is equivalent to a control (control
means or control method), with which, in a case where an error
occurs (occurrence of an error is determined), the status of the
sensor value can be rendered substantially the same as before the
occurrence of the error, and thus the driving status (operation
status) of the active mechanism 7A can be maintained.
[0103] On the other hand, in the variant example as will be
described below, a driving control (process) at an occurrence of an
error is controlled to be carried out in a manner similar to that
before the occurrence of the error.
[0104] As a specific example for such case, as shown in FIG. 7, for
instance, an angular change between an angle .theta.2 of a sensor
value at point C just before the occurrence of the error and an
angle .theta.2' of a sensor value at point C' a unit time .DELTA.t2
before point C is considered .DELTA..theta.c.
[0105] In this case, an angle .DELTA.3 of a sensor value at point D
at the occurrence of the error is not used, while a value that can
be derived by adding the angle .DELTA.2 of the sensor value at
point C and the angular change .DELTA..theta.c is rendered a sensor
value .DELTA.3' or a replacement signal.
[0106] In other words, in the occurrence of the error, the control
section 10A (or the replacement section 16) generates a driving
signal in the following manner.
[0107] In the occurrence of the error, the control section 10A does
not use the current sensor value, but replaces that sensor value
with a previous error-free sensor value acquired just before. Along
with that, the control section 10A generates a driving signal to be
used from the time after the occurrence of the error by adding an
amount of change, which can be estimated based on a value of the
previous sensor value (an angular velocity if the sensor value is
of an angle) as it comes up to the point where the error has
occurred, to the previous sensor value.
[0108] Moreover, the determination section 12, for example, stores
the value of ".theta.3-0.theta.'" in the memory section 15, etc. as
a correction value W, and uses that correction value W to correct
the sensor values acquired after the point where the error has
occurred.
[0109] In such case, the sensor values at points D, E and F shown
in FIG. 3B will be corrected such that they will become as sensor
values at points D'', E'' and F''' shown in FIG. 7.
[0110] By adopting the error process of this variant example, in
such case where the amount of angular change per unit time is
small, it is possible to carry out the control while restraining
possible decrease in responsiveness.
[0111] In addition, as a second variant example, it is possible to
use a temporal average value with respect to the angular change
before the occurrence of the error, instead of the angular change
.DELTA..theta.c.
[0112] Specifically, an average angular change
<.DELTA..theta.c>(=(.theta.2-.theta.2'')/(t(c)-t(c''))) in a
period of time from point C'', which is further before point C',
where a sensor value of an angle .theta.2'' was acquired up to
point C where the sensor value of the angle .theta.2 was acquired
can be used instead of the angular change .DELTA..theta.c. Here,
t(c) and t(c'') indicate times at point C and point C'',
respectively.
[0113] It is possible to arrange such that a user can select from
among the error process according to the first embodiment and the
error processes according to the variant examples.
[0114] Next, with reference to FIG. 8, a specific configuration
example of the endoscope treatment system 1 shown in FIG. 1 will be
described. FIG. 8 shows specific configuration examples of the
endoscope 2 and so forth.
[0115] The endoscope 2 has an elongated insertion section 21 to be
inserted into a body, an operation section 22 arranged at a
posterior end of the insertion section 21 and a universal cable 23
extending from the operation section 22. An end portion of the
universal cable 23 is connected to the light source device 4, the
display processor 5 and the control device 8 through connectors,
which are not shown, in detachable manners.
[0116] The insertion section 21 has a distal end section 24
arranged at a distal end thereof, a bendable bending section 25
arranged at a posterior end of the distal end section 24, and a
flexible section 26 which exhibit flexibility in a length between a
posterior end of the bending section 25 and an anterior end of the
operation section 22. The bending section 25 is actively
bend-driven by a motor unit 35 arranged inside the operation
section 22.
[0117] The distal end section 24 has an illumination window and an
observation window arranged thereat. The illumination window has a
distal end surface of a light guide 27 attached thereto. This light
guide 27 has a posterior end thereof connected to the light source
device 4 through the insertion section 21, the operation section 22
and the universal cable 23, and will transmit illuminating light
from the light source device 4 in order to emit the illuminating
light from its distal end surface.
[0118] In stead of the light guide 27, a light-emitting diode (to
be referred to as LED) may be arranged at the distal end section 24
to use the light emitted from the LED as the illuminating
light.
[0119] A subject, such as an affected part inside a body, as being
irradiated with the illuminating light emitted through the
illumination window will be formed into an optical image by an
objective lens 28 attached to the observation window. A
charge-coupled device (to be referred to as CCD) 29, for example,
is arranged at an image forming position, and photoelectric
conversion is carried out by this CCD 29.
[0120] The CCD 29 is connected to the display processor 5 through a
signal line which is being inserted inside the insertion section
21, etc. The CCD 29 will output a photoelectric-converted image
pickup signal in response to a CCD driving signal supplied from a
CCD drive circuit 30 arranged inside the display processor 5.
[0121] This image pickup signal will be inputted to a video signal
generation circuit 31 arranged inside the display processor 5 where
it will be converted into a video signal. Then the video signal
will be inputted to the display device 6, whereby the optical image
having been formed on an image-pickup surface of the CCD 29 will be
displayed on a display surface of the display device 6 as an
endoscope image.
[0122] A treatment instrument insertion opening (to be referred to
as insertion opening) 32a is arranged around the posterior end of
the insertion section 21, i.e. around the anterior end of the
operation section 22. The insertion opening 32a is in communication
with a treatment instrument channel (to be referred to as channel)
32 which is formed in a longitudinal direction of the insertion
section 21.
[0123] The treatment instrument 3, from the distal end side
thereof, can be inserted into the treatment instrument channel 32
through the treatment instrument insertion opening 32a. Then the
distal end of the treatment instrument 3 can be projected from a
distal end opening of the channel 32, whereby the treatment
instrument 3 will be able to perform a treatment such as resecting
a lesioned part, or the like, for instance.
[0124] The bending section 25 has a plurality of circular bending
pieces or joint pieces (to be referred to as joints) 33, 33, . . .
, 33 being connected through pivoted members such as rivets, in a
turnable manner. The pivoted members can be arranged, for instance,
at upper and lower positions and at right and left positions.
[0125] For the purpose of bend-driving the plurality of joints 33,
33, . . . , 33 that configure the bending section 25, up and down
bending wires 34u and 34d, and left and right bending wires 34l and
34r are inserted inside the insertion section 21. A distal end of
each wire 34j (=u, d, l, r) is fixed to the joint 33 at the
farthest end or to the distal end section 24 to which the joint 33
at the farthest end is connected.
[0126] Posterior ends of the paired wires 34u and 34d, and
posterior ends of the paired wires 34l and 34r are winded, for
example, around an up-and-down bending pulley 36a and a
right-and-left bending pulley 36b, respectively. The up-and-down
bending pulley 36a and the right-and-left bending pulley 36b are
arranged inside the motor unit 35 which configures the active
mechanism 7A that actively drives the bending section 25, while the
motor unit 35 is being arranged inside the operation section
22.
[0127] With this configuration, one of the wires 34u and 34d can be
pulled while the other can be relaxed, for example, by causing the
pulley 36a to turn (rotate), whereby the joints 33, 33, . . . , 33
of the bending section 25 can be bend-driven toward the pulled
wire.
[0128] The pulleys 36a and 36b are connected to rotation axes of an
up-and-down bending motor 37a and a right-and-left bending motor
37b, respectively, through gears, which are not shown. Rotation
angles of the respective motors 37a and 37b (or rotation angles of
the respective pulleys 36a and 36b) that configure a rotary drive
section will be detected by respective rotary encoders (to be
referred to as encoders) 38a and 38b that configure the sensor
11A.
[0129] The motors 37a and 37b are rotary driven with driving
signals supplied from a motor drive circuit 41A arranged inside the
control section 10A that configures a control device 8A (for
endoscope) inside the control device 8, whereby the wires 34u, 34d,
34l and 34r are pulled/relaxed to actively drive the bending
section 25.
[0130] Encoder output signals (as sensor values) outputted from the
encoders 38a and 38b will be inputted to a control circuit 42A
inside the control section 10A through an A/D conversion circuit
43A as digital operation status signals (specifically, detected
angles). These digital operation status signals will be inputted to
a determination section 12A as well.
[0131] A signal (as an instruction input signal) with respect to
bending direction and angle, corresponding to an instruction input
operation by the user, will also be inputted to the control circuit
42A through a joystick 44A, which is a specific example of the
instruction input device 9A.
[0132] The control circuit 42A, in a usual (normal) case, takes a
signal of a difference value derived by subtracting the encoder
output signal from the instruction input signal as a new
instruction input signal, and outputs this new instruction input
signal to the motor drive circuit 41A. Then the motor drive circuit
41A will output driving signals corresponding to such instruction
input signal to the motors 37a and 37b.
[0133] Meanwhile, in such event that the encoder output signal is
determined as invalid through a determination process by the
determination section 12A, as will be described bellow, the motor
drive circuit 41 takes in a replacement signal from a replacement
section 16A inside the determination section 12A to use the
replacement signal as a new instruction input signal, and outputs
that instruction input signal to the motor drive circuit 41A. That
is, in an unusual (abnormal) case, generation of the driving
signals by the motor drive circuit 41A is controlled by the
replacement signal from the determination section 12A.
[0134] Therefore, the encoder output signals outputted from the
encoders 38a and 38b will also be inputted to the determination
section 12A through the A/D conversion circuit 43. These encoder
output signals will be stored in a memory section 15A inside the
determination section 12A.
[0135] Moreover, in the present embodiment, a motor characteristic
storage section 13A where motor characteristics of the motors 37a
and 37b are stored is provided. Data on the motor characteristics
will be inputted to a setting section 14A.
[0136] The setting section 14A sets allowable operation ranges
based on the motor characteristics and the instruction input signal
(or an updated instruction input signal generated by the control
circuit 42A).
[0137] Furthermore, the determination section 12A, for example,
detects (acquires) information on an angle directly from the
encoder output signal, while the determination section 12A
calculates by a calculation section 17A therein an angular velocity
based on time dependent change in the angle, and an angular
acceleration based on time dependent change in the angular
velocity.
[0138] Then based on the information on the allowable operation
ranges as being set by the setting section 14A, the determination
section 12A performs validity determination to determine whether
the angle (or the angular change), the angular velocity and the
angular acceleration, regarded as the operation status signal, are
within or deviating from the allowable operation ranges.
[0139] As described above, when the operation status signal is
found to be within the allowable operation range, the control
section 10A that configures a driving signal generation section
uses the encoder output signal, i.e. information on the angle, to
generate a new driving signal.
[0140] On the other hand, when the operation status signal is
determined as deviating from the allowable operation range, the
control section 10A reads out from the memory section 15A, where
the encoder output signals are stored in time series, the latest
previous signal (i.e. a signal at a time just before the operation
status signal has been determined as being deviating from the
allowable operation range) corresponding to the encoder output
signal with which the operation status signal has been determined
as being within the allowable operation range.
[0141] Then the determination section 12A outputs the read out
signal to the control circuit 42A as a replacement signal. The
control circuit 42A takes the replacement signal as the operation
status signal of the usual case to generate a subsequent driving
signal.
[0142] Thus, in the present embodiment, the detection signals of
the encoders 38a and 38b functioning as sensors and the signals
indicating the time-dependent changes in the values of the
detection signals are monitored. Then in the case when the
monitored signals are determined as being within the allowable
operation ranges, it is controlled such that the driving signal is
generated based on the detection signals of the encoders 38a and
38b. On the other hand, in the case when the monitored signals are
determined as being abnormal because of deviating from the
allowable operation ranges, it is controlled such that the driving
signal is generated based on the latest previous detection signals
of the encoders 38a and 38b having been determined as normal.
[0143] In the case when the monitored signals are determined as
abnormal, and it comes to the state that the driving signal needs
to be controlled based on the prior detection signals of the
encoders 38a and 38b which have been determined as normal, the
determination section 12A outputs a signal for informing that
abnormal status directed to the video signal generation circuit 31
of the display processor 5. Thereby, displays indicating that
abnormal status has been determined, and that the driving operation
is proceeding based on the latest detection signals of the encoders
38a and 38b will be put on the display surface of the display
device 6. Moreover, it is also possible to arrange such that
information on the determination result in the normal status can be
indicated, in addition to indicating the state of determination
result in the abnormal status.
[0144] In such a case where an operator, such as a surgeon, is in
the middle of performing an endoscope examination, bending control
on the bending section 25 can be executed continuously.
[0145] By executing such control, even in a case when the detection
signals of the encoders 38a and 38b are found deviating from the
allowable operation ranges due to noise, for example, the operation
can be continued based on the detection signals of the encoders 38a
and 38b acquired at the time just before the occurrence of the
noise.
[0146] In other words, in a case when the detection signals of the
encoders 38a and 38b are found deviating from the allowable
operation ranges due to noise, for example, the current detection
signals of the encoders 38a and 38b are not used in controlling the
drive section, but the operation is made to continue based on the
detection signals of the encoders 38a and 38b in the normal case
acquired at the time just before the occurrence of the noise.
[0147] Such condition in the case where the detection signals of
the encoders 38a and 38b are found deviating from the allowable
operation ranges due to noise is almost equivalent to a condition
in which the control status or the operation status where the
normal status at the time just before the deviance has found is
maintained can be kept, with only a temporal response rate decrease
in a short period of time.
[0148] Then, after that, when a normal status is determined by the
determination section 12, the drive section will be controlled by
the detection signals of the encoders 38a and 38b again. In this
way, in the case when the detection signals of the sensors are
found to be deviating from the allowable operation ranges due to
noise, it is possible to control to maintain the control status at
a nearly appropriate state and allow the bend-driving of the
bending section 25 to be continued.
[0149] On the other hand, FIG. 9 shows a configuration of the
treatment instrument 3 to be inserted into the channel 32 of the
endoscope 2. As shown in FIG. 9, the treatment instrument 3 has an
elongated axis section 51 (as a treatment instrument insertion
section), for instance, which can be inserted into the channel 32.
A treatment section 52, which is used in performing a treatment
such as resection, is formed at a distal end of this axis section
51.
[0150] At a posterior end of the treatment section 52, a bending
section (flexion section) 55 is formed. The bending section 55 has
a plurality of joints 53a, 53b, . . . . 53d being connected through
pivoted sections 54a, 54b and 54c in a turnable manner, the pivoted
sections 54a, 54b and 54c being arranged adjacent to and in a
longitudinal direction of the joints 53a, 53b, . . . , 53d.
[0151] At a posterior end of the axis section 51, a motor box 56 as
being a drive section for electrically driving the bending section
55 is arranged. A cable 67 which extends from this motor box 56 is
connected to a control device 8B (for treatment instrument).
[0152] In FIG. 9, for example, the joint 53a at the farthest end to
which a proximal end of the treatment section 52 is fixed is
rotatably connected to the adjacent joint 53b through the pivoted
section 54a, in a vertical direction with respect to the paper
surface, for example.
[0153] Wires 57a and 57a which transmit driving force for
rotational movement have distal ends thereof fixed to a direct
front position of the pivoted section 54a at the joint 53a. These
wires 57a and 57a are being inserted inside the joints 53b, . . . ,
53d, and winded around a pulley 58a arranged inside the motor box
56.
[0154] This pulley 58a is connected to a rotation axis of a motor
59a with which rotation the pulley 58a can be rotated. An encoder
60a which functions as a sensor for detecting (acquiring) a
rotation angle of the motor 59a is connected to the rotation axis
of the motor 59a.
[0155] The joint 53b (or the pivoted section 54b between the joints
53b and 53c) and the joint 53c (or the pivoted section 54c between
the joints 53c and 53d) can be rotated with a similar
configuration.
[0156] That is, the joint 53b is connected to a pulley 58b inside
the motor box 56 through wires 57b and 57b which are inserted
inside the joints 53c and 53d and winded around the pulley 58b, the
pulley 58b being connected to a rotation axis of a motor 59b, and
the rotation axis of the motor 59b being connected to an encoder
60b which functions as a sensor for detecting (acquiring) a
rotation angle of the motor 59b.
[0157] Furthermore, the joint 53c is connected to a pulley 58c
inside the motor box 56 through wires 57c and 57c which are
inserted inside the joint 53d and winded around the pulley 58c, the
pulley 58c being connected to a rotation axis of a motor 59c, and
the rotation axis of the motor 59c being connected to an encoder
60c.
[0158] The motors 59a to 59c inside the motor box 56 are connected
to a motor drive circuit 41B inside the control section 10B through
signal lines within a cable 67, and are driven with driving signals
supplied from the motor drive circuit 41B.
[0159] Output signals from the encoders 60a to 60c will be inputted
to an A/D conversion circuit 43B inside the control section 10B
through the signal lines within the cable 67. The A/D converted
digital signals from the A/D conversion circuit 43B will be
inputted to a determination section 12B and a control circuit
42B.
[0160] A signal with respect to the angle for bending (turning) the
pivoted sections 54a to 54c among the plurality of joints that
configure the bending section 55, corresponding to an instruction
input operation by the user, will be inputted to the control
circuit 42B as an instruction input signal through a joystick 44B,
which is a specific example of the instruction input device 9B.
[0161] The control circuit 42B, in a usual (normal) case, takes a
signal of a difference value derived by subtracting the encoder
output signal from the instruction input signal as a new
instruction input signal, and outputs this new instruction input
signal to the motor drive circuit 41B. Then the motor drive circuit
41B will output driving signals corresponding to such instruction
input signal to the motors 59a to 59c.
[0162] The control device 8A as shown in FIG. 8 has the
configuration for drive controlling the two motors 37a and 37b,
whereas the control device shown in FIG. 9 has the configuration
for drive controlling the three motors 59a to 59c.
[0163] As with the configuration of the control device 8A shown in
FIG. 8, the control device 8B shown in FIG. 9 also includes a motor
characteristic storage section 13B and a setting section 14B. The
motor characteristic storage section 13B and the setting section
14B have similar functions to the motor characteristic storage
section 13A and the setting section 14A as described with reference
to FIG. 8.
[0164] Moreover, a memory section 15B, a replacement section 16B
and a calculation section 17B as arranged in the determination
section 12B have similar functions to the memory section 15A, the
replacement section 16A and the calculation section 17A as arranged
in the determination section 12A, respectively.
[0165] With respect to an operation in a case when the joints 33,
33, . . . , 33 of the bending section 25 are drive-controlled using
the motor unit 35 of the endoscope 2 shown in FIG. 8, the operation
will be approximately the same as that in the case of FIG. 2
considering that the active mechanism 7A is replaced with motors
37a and 37b, and the sensor 11A is replaced with the encoders 38a
and 38b.
[0166] Likewise, with respect to an operation of the treatment
instrument 3, the operation will be approximately the same as that
in the case of FIG. 2, considering that the above-mentioned motors
37a and 37b are replaced with motors 59a to 59c, and the encoders
38a and 38b are replaced with encoders 60a to 60c.
[0167] Thus, according to the present embodiment, when the active
mechanism or the drive section is actively drive-operated with a
driving signal while the operation status is detected by the sensor
and the detected sensor value is used in drive controlling the
active mechanism or the drive section, even in such case where the
sensor value is found to be abnormal due to noise, etc., the drive
control can be executed based on the valid sensor value acquired at
the time just before the abnormal status has occurred, whereby the
operation can be continued without being forced to stop under
abnormal termination. Therefore, operability for a user can be
enhanced.
Second Embodiment
[0168] Now, with reference to FIG. 10, an endoscope treatment
system 1B that includes a second embodiment of the present
invention will be described. In the endoscope treatment system 1B
shown in FIG. 10, the treatment instrument 3 in the endoscope
treatment system 1 of FIG. 1 is an electric energy treatment
instrument, for instance, which has an energy treatment section 52a
arranged at a distal end portion thereof, the energy treatment
section 52a functioning to perform treatments using electric energy
such as high frequency electric energy, for example.
[0169] The present embodiment is provided with a decision section.
The decision section decides to execute or stop the determination
operation by the determination section according to a used or
unused status of an energy output device that outputs electric
energy (hereinafter to be referred to simply as energy), the energy
output device being an external device of the manipulator 20.
[0170] Moreover, this treatment instrument 3 has the active
mechanism 7B which is provided with the bending section 55 arranged
around a posterior end of a distal end portion thereof, as shown in
FIG. 9, for example.
[0171] This endoscope treatment system 1B has an energy output
instruction input device (to be referred to simply as instruction
input device) 61 which provides an instruction input on energy
output, and an energy output device 62 which outputs energy such as
high frequency electric energy, in response to the instruction
input on the energy output.
[0172] This energy will be applied through the energy treatment
section 52a at the distal end of the treatment instrument 3 to a
treatment target region, such as a lesioned part, inside a body,
whereby a treatment such as resection, by energy can be
performed.
[0173] In the present embodiment, the energy output device 62
outputs ON/OFF information on energy output to the determination
section 12. Based on the ON/OFF information on energy output as
being information on an operation environment including a used or
unused status of the energy output device, the determination
section 12 automatically determines whether the determination
operation for determining whether or not the sensor value is normal
is to be executed or not.
[0174] Specifically, in a period where the energy output is ON
(i.e. in an operation environment where the energy output device is
used), the determination operation for determining whether or not
the sensor value is valid is executed as in the case of the first
embodiment, whereas in a period where the energy output is OFF
(i.e. in an operation environment where the energy output device is
not used), the determination operation for determining whether or
not the sensor value is valid is not executed (i.e. the
determination operation is stopped).
[0175] The present embodiment is a case that copes with a situation
where the operation is carried out with the sensor value of the
sensor 11A or 11B being at a sufficiently highly reliable state
(even without the validity determination) while energy is not
outputted from the energy output device 62, while there is a
possibility, only during the period where energy is outputted, that
the sensor value becomes susceptible to the energy from the energy
output device 62 for the energy could be taken as noise. The rest
of the configuration is the same as that in the first
embodiment.
[0176] Next, an operation in the present embodiment will be
described with reference to a flow chart of FIG. 11. The following
description will be about a case of an operation in terms of the
treatment instrument 3.
[0177] The operation starts when power is supplied to the endoscope
treatment system 1B shown in FIG. 10. Then at an initial step S21
in FIG. 11, the determination section 12 determines whether the
instruction input device 61 has requested the energy output device
62 for energy output, i.e. whether or not an energy output
instruction is ON.
[0178] When the output instruction is ON, the determination section
12, at step S22, acquires a sensor value from the sensor 11B.
(Here, it is also possible to arrange such that at an initial point
when the output instruction is switched from OFF to ON, the sensor
value is acquired before the energy output.)
[0179] Then according to the acquired sensor value, the
determination section 12, at a subsequent step S23, executes a
determination process for determining the validity of the sensor
value (i.e. determining whether or not there is an error).
[0180] Then at a subsequent step S24, the control section 10B
generates a driving signal for driving the active mechanism 7B
based on the determination result by the determination section 12,
and thus controls the active mechanism 7B.
[0181] Specifically, when it is determined that the sensor value is
valid, the control section 10B, at step S25, generates (controls) a
driving signal for driving the active mechanism 7B using that
sensor value. On the other hand, when the determination section 12
determines that there is an error and thus outputs a replacement
signal, the control section 10B, at step S26, takes that
replacement signal as a sensor value to generate a driving signal
for driving the active mechanism 7B. This process may be executed
by the replacement section 16 instead of the control section
10B.
[0182] Meanwhile, at step S21, when the output instruction is not
ON, i.e. when the output instruction is OFF, the determination
section 12, at step S27, acquires a sensor value from the sensor
11B.
[0183] Then after the process at step S27, the operation proceeds
to step S25 where a driving signal is generated based on the
acquired sensor value.
[0184] In this way, when the output instruction is OFF, the
determination process for determining the validity is not executed
with respect to the acquired sensor value, while the driving signal
is generated based on that acquired sensor value.
[0185] According to the present embodiment, by executing the
processes as shown in FIG. 11, while energy is not outputted from
the energy output device 62, it is possible to eliminate the
determination process with respect to the validity of the sensor
value and the subsequent process in the case when the sensor value
is found to be an error through the validity determination process.
Thereby, possible decrease in responsiveness can be prevented.
[0186] Other advantageous effects that can be achieved in the
present embodiment are similar to those in the first
embodiment.
[0187] Although the present embodiment adopts decision means that
automatically decides that the determination process with respect
to validity of the sensor value should be executed or not based on
the ON or OFF status of the output instruction, it is also possible
to arrange such that a user can choose whether the determination
process with respect to validity of the sensor value should be
executed or not through an input device or the like, which is not
shown.
[0188] Moreover, although the example of the operation as described
with reference to FIG. 11 is about the operation in the case of
drive controlling the active mechanism 7B of the treatment
instrument 3, similar operation can be applied in the case of drive
controlling the active mechanism 7A of the endoscope 2.
[0189] Furthermore, as in the configuration shown in FIG. 8, for
example, in the case when the determination section 12A takes in
the sensor values from the encoders 38a and 38b through the A/D
conversion circuit 43, it is possible to arrange such that the
output signals of the encoders 38a and 38b taken as the sensor
values in forms of pulse signals can be determined whether they are
valid or not based on whether the periods or frequencies of the
pulse signals are within predetermined ranges (this arrangement can
also be applied to the case of FIG. 9).
[0190] Accordingly, as shown in FIG. 12, for example, it is
possible to arrange such that a value of the sensor value having
been A/D converted by the A/D conversion circuit 43A is inputted to
the determination section 12A through a frequency analysis section
71 (or a filter section with a plurality of filters having
different pass bands), and the determination section 12A determines
whether the sensor value is valid or not based on the analysis by
the analysis section 71, etc. showing whether the input signal
directed to the determination section 12A is within a predetermined
frequency band.
[0191] For example, considering a case where an energy output
device or the like is used, frequency of the energy form the energy
output device will usually become higher than that of the pulse
signals outputted from the encoders 38a and 38b as being based on
rotation.
[0192] In such case, it is possible to arrange such that the sensor
value will be determined as invalid or an error due to noise
brought in by the energy output device 62, if the input signal
analyzed by the frequency analysis section 71, etc. is found to be
in a higher band side than the predetermined frequency band (which
can be considered appropriate as a frequency band of a sensor
value).
[0193] In this way, it is possible to have the validity of the
sensor value determined based on the frequency analysis, etc., of
the detection signal of the sensor. Then, as described above, in
such event when an error is determined, the driving control may be
executed using the sensor value acquired at the time just before
the error has been determined.
[0194] The arrangement, the process, etc., related to frequency
analysis as described above can also be applied to a case in which
a sensor value is to be taken in not through the A/D conversion
circuit 43A.
[0195] The above-described embodiments, etc., have been described
as the cases of the manipulator having the bending section 25 or 55
with the plurality of turnable joints 33 or 53 to 53d. However, it
is obvious that the above-described embodiments, etc. can be
applied to a case of driving a manipulator with a single joint.
Moreover, the above-described embodiments, etc. can be applied to a
case of driving an actuator with a plurality of joints.
[0196] Furthermore, the above-described embodiments, etc. can be
applied to a case of a manipulator which is configured in such a
way that the joints 33, etc. can be rotated around an insertion
axis (arranged in a longitudinal direction) of the insertion
section 2 1.
[0197] Moreover, the operation status signal is not limited to the
one that includes information on three of the angle, the angular
velocity and the angular acceleration, but can include information
on the angle only, or information on the angle and the angular
velocity. In other words, it is possible to arrange such that the
calculation section 17 calculates only the angular velocity or only
the angular acceleration based on the angle, and the determination
section determines whether the angle and the angular velocity or
the angular acceleration are within allowable operation ranges.
[0198] Embodiments which can be configured by partially combining
the above-described embodiments, etc. belong to the present
invention as well.
* * * * *